A Case of a Rectal Gastrointestinal Stromal Tumor: An Unexpected Cause of Lower Gastrointestinal Bleeding in an Immunocompromised Man

GISTs are rare, with only around 5,000 cases diagnosed annually in the United States. However, these tumors are the most common mesenchymal neoplasm in the gastrointestinal (GI) tract. 5%-15% of GISTS arise in the colon and rectum. Most GISTs are diagnosed incidentally on imaging, endoscopy, or during a surgical procedure.